An internal combustion engine using wobble elements to generate torque is described in U.S. Pat. No. 2,513,083 in which each wobble element consists of a hollow circular ring body and a circular disk pivotally supported within the ring body. The disk is linked with the output shaft in a non-rotatable manner (i.e. is constrained to rotate with the shaft) and is supported at an angle thereto. From the outer peripheral areas of the ring body radially project pins which engege in stationary guide slots extending parallel to the output shaft.
This system has, however, the disadvantage that the four pins of each ring body are subjected to a considerable stress within the guide slots since they are axially displaced in the slots under load and simultaneously laterally pressed and twisted against the slot walls. This causes a dissipation of a major portion of the drive power transmitted by the pistons. Moreover, the mechanical wear between the pins and the guide slots is rather high and a reliable lubrication in this area is also very difficult, thus resulting in a very low working speed of the internal combustion engine.
In U.S. Pat. No. 1,476,275, an internal combustion engine is disclosed in which each wobble element has a circular gear rim at its inner side facing the housing of the engine. Cooperating with the gear rim is a further congruent gear rim fixed to the housing. The gear rim of the wobble element rolls upon the gear rim of the housing in order to prevent the wobble element from rotating with the output shaft.
This leads to a significant mechanical wear and to undesired running noises between the gear rims.
A further drawback is that the support of the connecting rods of all pistons have fixed arc spacings in a circumferential direction of the wobble element which results in a bending of the connecting rods perpendicular to the piston pins during the wobble motion of the wobble element, these bending stresses being transmitted onto the pistons within the cylinders. Due to the resulting kinematic swinging movement of each connecting rod about the piston pin, an oscillating motion is obtained for each piston so that the cylinder wall is unevenly loaded which results in considerable mechanical wear.